1231169221 has 2 divisors, whose sum is σ = 1231169222. Its totient is φ = 1231169220.

The previous prime is 1231169213. The next prime is 1231169263. The reversal of 1231169221 is 1229611321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1223250625 + 7918596 = 34975^2 + 2814^2 .

It is a cyclic number.

It is not a de Polignac number, because 1231169221 - 2³ = 1231169213 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1231169221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1231169321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 615584610 + 615584611.

It is an arithmetic number, because the mean of its divisors is an integer number (615584611).

Almost surely, 2^1231169221 is an apocalyptic number.

It is an amenable number.

1231169221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1231169221 is an equidigital number, since it uses as much as digits as its factorization.

1231169221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1296, while the sum is 28.

The square root of 1231169221 is about 35088.0210470753. The cubic root of 1231169221 is about 1071.7806612606.

The spelling of 1231169221 in words is "one billion, two hundred thirty-one million, one hundred sixty-nine thousand, two hundred twenty-one".